Speaker
Description
The event reconstruction in the CBM experiment is challenging.
There will be no simple hardware trigger due to the novel concepts of free-streaming data and self-triggered front-end electronics.
Thus, there is no a priori association of signals to physical events.
CBM will operate at interaction rates of 10 MHz, unprecedented for heavy ion experiments.
At this rate, collisions overlap in time and are to be resolved in software by reconstruction algorithms.
These complications made the speed and quality of the data reconstruction crucial.
The core of the track reconstruction is the Cellular Automaton (CA) based algorithm used for the Silicon Tracking System (STS).
It digests free-streaming data both online and offline, taking large time slices of the hit measurements as input with non-a priori-defined physical collisions.
The data is reconstructed in time portions by applying a nonmerging sliding window algorithm, which achieves almost constant
time per event regardless of the time slice size.
The algorithm was successfully applied to run online for the mini-CBM experiment during the March 2024 data-taking campaign.
